Apparatus and method for interfacing between communication networks
AssigneeFujitsu Limited
InventorsKeiichiro Tsukamoto, Akihiko Oka
Life of this patent
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Abstract
Conventionally, since in an ADM apparatus being an interface apparatus between a DS3 network and a SONET network a DS3 frame is mapped into an STS1 frame, the multiplexing and demultiplexing of the STS1 frame has to be carried out in units of DS3 frames. For this reason, the DS3 frame is demultiplexed and converted to a DS2 frame, and then to a DS1 frame, the DS1 frame is multiplexed and converted to a VT1.5 frame, and this VT1.5 frame is mapped into an STS1 frame. Since the VT1.5 frame is synchronized with the STS1 frame, the multiplexing and demultiplexing processes can be carried out in smaller units of the VT1.5 frame. Accordingly, data can be distributed on smaller units on a network.
Claims19
An interface apparatus for supporting the demultiplexing and multiplexing of signals in units of VT1.5 in a SONET network by converting a DS3 signal to a VT1.5 signal, and providing a direct interface to a DS3 network, comprising:
- DS3/DS2 demultiplexing means for demultiplexing and converting a DS3 signal to DS2 signals;
- DS2/DS1 demultiplexing means for demultiplexing and converting DS2 signals to DS1 signals;
- memory means for DS1 format conversion for recording data in order to compensate for a frequency off-set generated while demultiplexing and converting a DS3 signal to DS1 signals via DS2 signals, and outputting data synchronized with a supplied clock;
- clock generating means for a SONET VT network for supplying a clock signal in order to output data stored in said memory means for DS1 format conversion at the data rate of the SONET VT network;
- DS1/VT1.5 multiplexing means for multiplexing and converting DS1 signals to a VT1.5 signal synchronized with the clock generated by said clock generating means for a SONET VT network;
- VT1.5/STS1 multiplexing means for multiplexing and converting VT1.5 signals to an STS1 signal;
- STS1/VT1.5 demultiplexing means for demultiplexing and converting an STS1 signal to VT1.5 signals;
- VT1.5/DS1 demultiplexing means for demultiplexing and converting VT1.5 signals to DS1 signals;
- clock generating means for a DS3 network for generating a clock signal synchronous with the data rate of the DS3 network;
- DS1 clock generating means for generating a clock signal synchronous with a DS1 signal;
- memory means for SONET destuff for storing data in order to compensate for a frequency off-set generated while demultiplexing and converting an STS1 signal to DS1 signals via VT1.5 signals, and outputting data synchronized with the clock signal generated by said DS1 clock generating means;
- DS1/DS2 multiplexing means for multiplexing and converting DS1 signals to DS2 signals synchronized with the clock signal generated by said clock generating means for said DS3 network;
- DS2/DS3 multiplexing means for multiplexing and converting DS2 signals to a DS3 signal synchronized with the clock signal generated by said clock generating means for said DS3 network.
An interface apparatus between a first network supporting data signals with a plurality of different transmission rates and a second network not synchronous with the first network, and with a higher transmission rate than the first network, comprising:
- demultiplexing means for demultiplexing and converting by stages the data signal of said first network from a data signal with a higher transmission rate to a data signal with a lower transmission rate, generating a data signal with the lowest transmission rate, and extracting failure information on each stage of the demultiplexing and conversion;
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- multiplexing means for inserting said failure information in said data signal with the lowest transmission rate, multiplexing and converting said data signal with the lowest transmission rate to a first data signal with a low transmission rate supported by said second network, and multiplexing and converting the first data signal to a second data signal with a standard transmission rate supported by said second network.
A method of interfacing between a first network supporting data signals with a plurality of different transmission rates, and a second network not synchronous with the first network, and with a higher transmission rate than the first network, comprising the steps of:
- (a) demultiplexing and converting by stages the data signal of said first network from a data signal with a higher transmission rate to a data signal with a lower transmission rate, generating a data signal with the lowest transmission rate, and extracting failure information on each stage of the demultiplexing and conversion;
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- (b) inserting said failure information in said data signal with the lowest transmission rate, multiplexing and converting said data signal with the lowest transmission rate to a first data signal with a low transmission rate supported by said second network, and multiplexing and converting the first data signal to a second data signal with a standard transmission rate supported by said second network.
An interface apparatus between a first network supporting data signals with a plurality of different transmission rates, and a second network not synchronous with the first network, and with a higher transmission rate than the first network, comprising:
- demultiplexing means for demultiplexing and converting a data signal with the standard transmission rate of said second network, to a data signal synchronous with a data signal with the standard transmission rate, and with a lower transmission rate than the standard transmission rate, demultiplexing and converting the data signal to a data signal with the lowest transmission rate of said first network, and extracting failure information on each stage of the demultiplexing and conversion;
- and
- inserting said failure information in said data signal with the lowest transmission rate of said first network, and multiplexing and converting by stages the data signal with the lowest transmission rate to a data signal supported by said first network, and with a higher transmission rate.
A method of interfacing between a first network supporting data signals with a plurality of different transmission rates, and a second network not synchronous with the first network, and with a higher transmission rate than the first network, comprising the steps of:
- (a) demultiplexing and converting the data signal with the standard transmission rate of said second network to a data signal synchronous with a data signal with the standard transmission rate, and with a data signal with a lower transmission rate than the standard transmission rate, demultiplexing and converting the data signal to a data signal with the lowest transmission rate of said first network, and extracting failure information on each stage of the demultiplexing and conversion;
- and
- (b) inserting said failure information in said data signal with the lowest transmission rate of said first network, and multiplexing and converting by stages said data signal with the lowest transmission rate to a data signal with a higher transmission rate supported by said first network.
Dependencies are inferred from the claim text.